Drunkard's Walk - Leonard Mlodinow [62]
The Clarks appealed the case and, for the appeal, hired their own statisticians as expert witnesses. They lost the appeal, but they continued to seek medical explanations for the deaths and in the process uncovered the fact that the pathologist working for the prosecution had withheld the fact that the second child had been suffering from a bacterial infection at the time of death, an infection that might have caused the infant’s death. Based on that discovery, a judge quashed the conviction, and after nearly three and a half years, Sally Clark was released from prison.
The renowned attorney and Harvard Law School professor Alan Dershowitz also successfully employed the prosecutor’s fallacy—to help defend O. J. Simpson in his trial for the murder of Simpson’s ex-wife, Nicole Brown Simpson, and a male companion. The trial of Simpson, a former football star, was one of the biggest media events of 1994–95. The police had plenty of evidence against him. They found a bloody glove at his estate that seemed to match one found at the murder scene. Bloodstains matching Nicole’s blood were found on the gloves, in his white Ford Bronco, on a pair of socks in his bedroom, and in his driveway and house. Moreover, DNA samples taken from blood at the crime scene matched O. J.’s. The defense could do little more than accuse the Los Angeles Police Department of racism—O. J. is African American—and criticize the integrity of the police and the authenticity of their evidence.
The prosecution made a decision to focus the opening of its case on O. J.’s propensity toward violence against Nicole. Prosecutors spent the first ten days of the trial entering evidence of his history of abusing her and claimed that this alone was a good reason to suspect him of her murder. As they put it, “a slap is a prelude to homicide.”14 The defense attorneys used this strategy as a launchpad for their accusations of duplicity, arguing that the prosecution had spent two weeks trying to mislead the jury and that the evidence that O. J. had battered Nicole on previous occasions meant nothing. Here is Dershowitz’s reasoning: 4 million women are battered annually by husbands and boyfriends in the United States, yet in 1992, according to the FBI Uniform Crime Reports, a total of 1,432, or 1 in 2,500, were killed by their husbands or boyfriends.15 Therefore, the defense retorted, few men who slap or beat their domestic partners go on to murder them. True? Yes. Convincing? Yes. Relevant? No. The relevant number is not the probability that a man who batters his wife will go on to kill her (1 in 2,500) but rather the probability that a battered wife who was murdered was murdered by her abuser. According to the Uniform Crime Reports for the United States and Its Possessions in 1993, the probability Dershowitz (or the prosecution) should have reported was this one: of all the battered women murdered in the United States in 1993, some 90 percent were killed by their abuser. That statistic was not mentioned at the trial.
As the hour of the verdict’s announcement approached, long-distance call volume dropped by half, trading volume on the New York Stock Exchange fell by 40 percent, and an estimated 100 million people turned to their televisions and radios to hear the verdict: not guilty. Dershowitz may have felt justified in misleading the jury because, in his words, “the courtroom oath—‘to tell the truth, the whole truth and nothing but the truth’—is applicable only